A major ratings firm announced Wednesday it is reviewing the debt of 30 cities - including Sacramento, Oakland and Fresno - because of the continuing economic pressures in the state.

Moody's Investor Services also announced it was looking to upgrade the ratings of Los Angeles and San Francisco because of steps the cities have taken to reduce their debt and manage their accounts.

Los Angeles also has deferred spending in a number of areas and taken steps to reduce the size of its workforce.

The reviews could affect up to $14.3 billion in bonds issued by cities throughout the state, the company said. Moody's is one of the major credit rating services that determine the interest cities pay to borrow money.

"California cities operate under more rigid revenue-raising constraints than cities in many other parts of the country," said Eric Hoffmann, who heads Moody's California local government ratings team.

"Combined with steeply rising costs, these constraints mean that these cities will likely recover more slowly than their peers nationally, even if the state's economic recovery tracks the nation's."

Los Angeles and San Francisco, however, have shown greater resiliency over the past several years while other cities have been forced into bankruptcy because of their debt.

San Bernardino, Stockton and Mammoth Lakes are among the cities that have declared bankruptcy.